Maintaining a healthy lifestyle through diet and exercise may help prevent certain diseases and enhance quality of life.

Antioxidants are the subject of increasing research because of the possible role they play in preventing disease. Antioxidants are molecules that work to prevent damage that occurs in cells and body tissues due to both normal bodily processes and exposure to some chemicals. The potential medical benefit of antioxidants may reside in their ability to prevent or slow the oxidation of molecules. However, there is some debate as to whether antioxidants have health benefits, as clinical trials have produced mixed results.

Research has recently focused on how antioxidant vitamins may reduce cardiovascular disease risk. In addition to being available in a variety of fruits and vegetables, antioxidants are available as supplements. Antioxidant vitamins, including vitamin E and C, and beta-carotene (a form of vitamin A), may have potential health benefits. According to the American Heart Association, approximately 30% of Americans are taking some form of antioxidant supplement.

Exercise is any form of physical activity that helps to promote overall health and decrease the risk of developing illnesses, such as heart disease. Most movement of the body is considered beneficial, as long as it is done in moderation and at the skill level of the person. There are many ways for people to exercise, including gardening, walking, sports activities, and dancing.

Patients beginning an exercise program should choose activities that fit their levels of strength and endurance. Exercise that causes extreme pain or discomfort is considered by many experts as unhealthy, and it may even cause permanent damage to the body.
Based on expert opinion, most regular exercise plans adjusted for the abilities and goals of the patient are about equally beneficial.

The American Academy of Family Physicians recommends that patients choose exercise programs they will carry out consistently. They also recommend lower-impact forms of exercise, such as walking or swimming, for pregnant patients and patients unable to handle more intense forms of exercise. The American Heart Association recommends that adults aged 18-65 years participate in moderate-intensity aerobic physical activity for a minimum of 30 minutes at least five days each week. Another option is vigorous-intensity aerobic activity for a minimum of 20 minutes at least three days each week.
The U.S. Centers for Disease Control and Prevention (CDC) recommends 30 minutes of moderate activity on all or most days of the week. Finally, the
World Health Organization (WHO) suggests 30 minutes of moderate activity every day.

According to the U.S. Department of Health and Human Services and the U.S. Department of Agriculture, poor diet and physical inactivity may be associated with a variety of conditions, including cardiovascular disease, type 2 diabetes, hypertension, osteoporosis, and certain cancers.

Rose hip: The evidence currently available supports the use of a rose hip fruit juice extract to support antioxidant status in healthy young adults. Some very preliminary data indicate that CiLi, an oral liquid prepared from the constituents of rose hips, may have immune-boosting properties.

Use cautiously in patients taking agents that affect the immune system, anticoagulant or anti-platelet aggregating agents, aluminum-containing antacids, salicylates, or laxatives. Avoid in patients who are allergic to rose hips, rose pollen, its constituents, or members of the Rosaceae family.

Use cautiously at doses from 27-2,310 milligrams daily, as well as in patients on hemodialysis, in patients with iodine deficiency, high cholesterol, or immune disorders, and in those using immunosuppressants, corticosteroids, antacids, erythropoietin (EPO), cholesterol-lowering medications, oral contraceptives, astragalus, or iron supplements. Avoid in patients at high risk of nonmelanoma skin cancers or at risk for developing diabetes. Avoid in patients with known allergy or hypersensitivity to products containing selenium; however, selenium is a trace element, and hypersensitivity is unlikely.

Strawberry: Laboratory studies suggest that strawberry has antioxidant properties. However, the effect in humans is unclear. Further study is needed to define strawberry's effectiveness in humans.

Use cautiously with hematological (blood) disorders or if taking anticoagulants or blood thinners. Use cautiously with iron-absorption disorder. Use cautiously if pregnant or breastfeeding. Avoid if allergic or hypersensitive to strawberry or members of the Rosaceae family.

Unclear or conflicting scientific evidence:

Amaranth: Limited evidence suggests that amaranth may have antioxidant properties when combined with a heart-healthy diet. Additional studies are needed before conclusions can be drawn.

Amaranth is generally considered safe. Avoid if allergic or sensitive to amaranth. Use cautiously with diabetes, low blood sugar, low blood pressure, immune system disorders, or kidney disorders. Use cautiously if pregnant or breastfeeding.

Ashwagandha: The use of ashwagandha as an antiaging agent is based on traditional use in Indian Ayurvedic medicine to promote physical and mental health, improve resistance to disease, and promote longevity. Preliminary research suggests antioxidant properties, which has been proposed by some as a possible mechanism of ashwagandha for promoting longevity. Human research is scant in this area, and currently there is insufficient evidence to draw a firm conclusion.

Avoid if allergic or hypersensitive to ashwagandha products or any of their ingredients. Dermatitis (allergic skin rash) was reported in three of 42 patients in one ashwagandha trial.There are few reports of adverse effects associated with ashwagandha, but there are few human trials using ashwagandha, and most do not report the doses or standardization/preparation used.Avoid with peptic ulcer disease. Ashwagandha may have cause abortions based on anecdotal reports. Avoid if pregnant or breastfeeding.

Beta-glucan: In patients with high blood pressure, foods containing oat beta-glucan did not appear to have antioxidant effects. More research is needed before a conclusion can be made.

Avoid if allergic or hypersensitive to beta-glucan. When taken by mouth, beta-glucan is generally considered safe. Use cautiously with AIDS or AIDS-related complex (ARC). Avoid using particulate beta-glucan. Avoid if pregnant or breastfeeding.

Avoid if allergic or hypersensitive to bitter orange or any members of the Rutaceae family. Avoid with preexisting cardiovascular (heart) disease, narrow-angle glaucoma, and intestinal colic. Avoid using if taking anti-adrenergic agents, beta-blockers, or QT-interval prolonging drugs or with long QT interval syndrome. Avoid if taking antidepressants, with drugs or dietary supplements with stimulant properties, and with honey. Use bitter orange preparations that are applied to the skin cautiously with fair skin. Use cautiously with headache and hyperthyroidism (too much thyroid hormone). Avoid if pregnant or breastfeeding.

Black currant: Preliminary study investigated the effects of black currant juice (and black currant anthocyanins in particular) on the steady state level of oxidative DNA damage in mononuclear blood cells. The antioxidant amount in the treatment dose was roughly equivalent to 10 servings of fruits and vegetables that have demonstrated antioxidant properties. The 22 elderly patients were dosed with black currant juice for only two weeks, a timeframe that other researchers determined to be inadequate to determine changes in antioxidant and oxidative status.

Avoid if allergic or hypersensitive to black currant, its constituents, or plants in the Saxifragaceae family. Avoid with hemophilia or those on blood thinners unless otherwise recommended by a qualified healthcare provider. Use cautiously with venous disorders or gastrointestinal disorders. Avoid if pregnant or breastfeeding.

Blackberry: Several in vitro studies indicate that blackberry fruit is high in antioxidants, which may be due to the berries' anthocyanin content, such as cyanidin-3-O-glucoside. However, its antioxidant properties in the laboratory did not translate to antioxidant properties in elderly humans when a mixed-fruit food was ingested for two weeks. The authors state that two weeks may not have been enough time for the fruit to change serum antioxidant levels. More research using blackberry as a monotherapy is needed to determine its effects on antioxidant levels in humans.

Avoid if allergic or hypersensitive to blackberry (Rubus fructicosus), its constituents, or members of the Rosaecae family. Based on traditional use, blackberry is likely safe in food amounts in pregnant or breastfeeding patients. Other uses are not recommended in pregnant or breastfeeding women due to lack of sufficient data.

Carrot: Several preliminary clinical studies indicate that carrot ingestion may have only slight antioxidant activity. Clinical study of smokers eating a controlled diet high in polyunsaturated fatty acids and ingestion of a combination of orange juice and carrot juice significantly reduced malondialdehyde levels, but did not affect LDL oxidation. More high-quality studies using carrot as a monotherapy are needed to define carrot's antioxidant activity in humans.

Avoid if allergic or hypersensitive to carrot, birch pollen-related allergens, or members of the Apiaceae family. Use cautiously in patients with low blood sugar or diabetes. Use cautiously in patients with bowel obstruction, hormone-sensitive conditions, or in children. Use cautiously and only in food amounts in pregnant and breastfeeding women.

Chocolate: Cocoa can be a rich source of flavonoids. These compounds may protect the body from the damaging effects of chemicals known as free radicals. More high-quality studies are needed before a conclusion can be made on the antioxidant effects of chocolate in humans.

Chocolate contains relatively high levels of caffeine. Use with caution in patients with addictive tendencies, anemia, cardiovascular disease, endocrine disorders, gastrointestinal disorders, kidney stones, migraine headaches, nervous disorders, respiratory disorders, or skin disorders. Use with caution in those who are overweight or obese or who are pregnant, breastfeeding, or trying to become pregnant. Use with caution in patients using agents that affect blood pressure, agents that affect blood sugar, antimicrobials, birth control pills, blood thinners, ergot derivatives, painkillers, sedatives, and stimulants. Use with caution in children. Avoid with known allergy or sensitivity to chocolate, cocoa, any of its components (including caffeine), or members of the Sterculiaceae family.

Cinnamon: Based on human study, a dried water-based extract of cinnamon (Cinnulin PF®) may improve the antioxidant status of overweight or obese individuals with impaired fasting glucose. More well-designed trials are needed before a firm conclusion can be made.

Avoid if allergic or hypersensitive to cinnamon, its constituents, members of the Lauraceae family, or Balsam of Peru. High levels of cinnamon may contain coumarin. Use cautiously if prone to atopic reactions or if taking cytochrome P450 metabolized agents, anticoagulants (blood thinners), insulin or blood sugar-altering medications, antibiotics, medications that affect the immune system, medications that lower cholesterol, agents toxic to the liver, or cardiovascular agents. Avoid if pregnant or breastfeeding.

Cordyceps: Cordyceps may improve various symptoms related to aging. However, higher quality studies testing specific symptoms of aging are needed before the specific effects of cordyceps can be determined.

Avoid if allergic or hypersensitive to cordyceps, mold or fungi. Use cautiously with diabetes, bleeding disorders or taking anticoagulant medications, with prostate conditions, if taking immunosuppressive medications, or if on hormonal replacement therapy or oral contraceptives. Avoid with myelogenous-type cancers. Avoid if pregnant or breastfeeding.

Cranberry: Based on laboratory study, cranberry may have antioxidant properties. However, human study is lacking. Further research is needed before a recommendation can be made.

Avoid if allergic to cranberries, blueberries or other plants of the Vaccinium species. Sweetened cranberry juice can affect blood sugar levels. Use cautiously with history of kidney stones. Avoid more than the amount usually found in foods if pregnant or breastfeeding.

Dandelion: Several laboratory studies report antioxidant properties for dandelion flower extract, although this research is preliminary, and effects in humans are not known.

Avoid if allergic to chamomile, feverfew, honey, yarrow, or any related plants such as aster, daisies, sunflower, chrysanthemum, mugwort, ragweed, or ragwort. Use cautiously with diabetes or bleeding disorders, gastroesophageal reflux disease (GERD), kidney or liver diseases, or a history of stroke or electrolyte disorders. Monitor potassium blood levels. Stop use two weeks before surgery/dental/diagnostic procedures with bleeding risk and do not use immediately after these procedures. Avoid if pregnant or breastfeeding.

Globe artichoke: Antioxidant properties of artichoke have been noted in multiple preclinical studies, although long-term clinical effects in humans are not known.

Use cautiously if allergic/hypersensitive to members of the Asteraceae or Compositae family (e.g., chrysanthemums, daisies, marigolds, ragweed, arnica), due to possible cross-reactivity. Use cautiously with cholelithiasis or biliary/bile duct obstruction or kidney disease. Avoid if pregnant or breastfeeding.

Grape seed: Studies have found grape seed to be an antioxidant that may help prevent or relieve symptoms of certain conditions, such as wound healing and vision problems associated with diabetes. The safety of long-term use of grape seed is unknown, and more studies are needed to provide definitive answers.

Avoid if allergic or hypersensitive to grapes or other grape compounds. Use cautiously if taking blood thinners such as warfarin, aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or anti-platelet agents. Use cautiously with bleeding disorders or if taking drugs that may increase the risk of bleeding. Use cautiously with drugs processed using the liver's "cytochrome P450" enzyme system. Use cautiously with blood pressure disorders or if taking ACE inhibitors. Avoid with disorders that increase their risk of bleeding or with active bleeding disorders (stomach ulcers, bleeding into the brain, etc.). Avoid if pregnant or breastfeeding.

Lignans: Lignans are thought to reduce blood lipid concentrations and improve antioxidant capacity. However, available research results are conflicting. Further studies are needed to confirm these results.

Use cautiously in patients with prostate abnormalities, clotting disorders, glucose or insulin disorders (including diabetes), low blood pressure, compromised immune systems, or in patients taking medications for these disorders. Use cautiously in patients taking CNS depressants, cytochrome P450 metabolized agents, diuretics, estrogens, or antibiotics. Use cautiously in pregnant or lactating women. Avoid in patients with known allergy/hypersensitivity to lignans, flaxseed, sesame seeds, or any plants that produce them.

Lutein: Numerous studies have shown the antioxidant effect of lutein in vitro. Epidemiological evidence suggests that consumption of additional lutein-rich foods has no effect on LDL oxidation. Results from clinical trials indicate that lutein has no effect on biochemical indices of oxidant status, reduced oxidative lymphocyte DNA damage, or oxidative stress. No firm conclusions can be drawn as to the ability of lutein to alter the antioxidant status of plasma at this time.

Avoid if allergic or hypersensitive to lutein or zeaxanthin. Use cautiously if at risk for cardiovascular disease or cancer. Avoid if pregnant or breastfeeding.

Lycopene: Like other carotenoids, lycopene is purported to possess antioxidant, antiradical, singlet oxygen quenching, and gap-junction communication enhancement activities. Multiple in vitro studies have demonstrated antioxidant properties, while a limited number of others have suggested a lack of these effects. Overall, lycopene does appear to exert antioxidant properties in vitro. In human studies, however, there have been mixed results in this area. Most trials have focused on serum lycopene levels or consumption of tomatoes or tomato-based products rather than intake of lycopene supplements. Therefore, it remains unclear to what extent lycopene supplements exert clinically relevant antioxidant effects in humans, or whether these potential effects alter the progression of any disease.

Avoid if allergic to tomatoes or to lycopene. Due to a lack of conclusive data, avoid if pregnant or breastfeeding.

Melatonin: There are well over 100 laboratory and animal studies of the antioxidant (free-radical scavenging) properties of melatonin. As a result, melatonin has been proposed as a supplement to prevent or treat many conditions that are associated with oxidative damage. However, well-designed trials in humans that demonstrate the benefits of melatonin as an antioxidant for any health problem are currently lacking.

Melatonin is generally considered safe in recommended doses for short-term use. Use cautiously with seizures, underlying major depression or psychotic disorders, high cholesterol, diabetes, blood sugar disorders, glaucoma, blood pressure disorders, bleeding disorders, or in patients using medications for any of these conditions. Use cautiously in patients using anesthetics, cytochrome P450 inhibitors, methamphetamine, nifedipine (a calcium channel blocker), or in children with a history of enuresis. Avoid in patients using CNS depressants, including benzodiazepines and alcohol. Avoid in women who are pregnant or are attempting to become pregnant. Avoid with known allergies to melatonin or related products.

Monterey pine: Antioxidant-rich plants such as Monterey pine (Pinus radiata) may offer protection against degenerative diseases and aging. Early studies showed that a combination of Monterey pine and vitamin C decreased cell damage from oxidation. Additional research is needed.

Use cautiously in patients taking blood pressure-lowering agents or those with blood pressure disorders, and in patients with high blood levels of fats or cholesterol. Avoid with known allergy or hypersensitivity to Monterey pine, its components (such as pollen), airborne allergens, or members of the Pinaceae family. Avoid during pregnancy or breastfeeding.

Noni: Laboratory studies indicated that Tahitian Noni® juice (TNJ) may have greater antioxidant activity than some commonly-used antioxidants. A human placebo controlled trial was conducted to determine any protective effects of TNJ on oxidative damage in smokers. Although the results suggest that TNJ does have antioxidant effects, whether TNJ protects smokers from oxidative damage is yet to be proven. More high-quality studies are needed in this area.

Avoid if allergic/hypersensitive to noni or any plants in the Rubiaceae family. Use cautiously with if taking warfarin or other blood "thinners." Use cautiously in patients with diabetes, low blood pressure, HIV/AIDS, compromised liver function, gastrointestinal disorders and blockages, or compromised kidney function. Avoid if pregnant or breastfeeding.

Palm oil: Palm oil and palm oil extracts have exhibited antioxidant properties in early research. In humans, palm oil has been reported to increase the resistance of VLDL (very low density lipoprotein) to oxidation when compared to sunflower oil. However, high-quality human studies in this area are lacking.

Use cautiously in patients with blood pressure disorders, abnormal cholesterol levels, gastrointestinal sensitivities, liver disorders, heart disease, bleeding disorders, or blood sugar disorders, or in patients taking medications for any of these disorders. Avoid oxidized palm oil. Avoid with known allergy or hypersensitivity to Elaeis guineensis, its constituents, or members of the Arecaceae family. Avoid in patients allergic to coconut, due to similarities in allergens. Avoid the use of large doses of palm oil in pregnant women, due to the risk of birth defects when vitamin A is consumed in doses greater than the recommend dietary allowance guidelines.

Papaya: Papaya has been shown to have potent antioxidant properties. Although early research results are encouraging, further studies are required before any conclusion can be made.

Papaya is likely safe when consumed in food amounts. Fermented papaya is possibly safe when used medicinally for up to three months. Use with caution in patients with bleeding disorders or those taking agents that may increase the risk of bleeding, in patients with diabetes or hypoglycemia or those taking agents that affect blood sugar, and in patients with autoimmune disorders or those using agents that affect the immune system. Use papaya seed extract and the papaya enzyme papain with caution. Use cautiously with vitamin A or retinoids, beta-carotene or carotene-containing foods, iron or iron-rich foods, sodium, potassium supplements, or agents that alter potassium levels. Avoid in patients with a known allergy or hypersensitivity to papaya, its components (including papaya juice, papaya flower pollen, papain, and chymopapain), members of the Caricaceae family, or latex. Cross sensitivity between kiwi and papaya, as well as papain, has been reported. Severe life-threatening allergic reactions to papain have been reported in approximately 1% of children receiving papain for burn treatment. Avoid high amounts of papaya seeds in women who are pregnant, breastfeeding, or trying to become pregnant.

Sweet peppers, such as paprika, are likely safe in amounts normally found in the diet. Avoid if allergic or hypersensitive to paprika, Capsicum annuum, other peppers, or plants related to these, or to latex. Sweet peppers should be washed before use and only purchased from trusted sources.

Parsley: A small clinical trial noted that parsley reduced oxidative stress. More research is needed to better determine the potential antioxidant effects of parsley.

Use cautiously with history of bleeding disorders, diabetes, hypotension, or digestive disorders. Avoid if allergic or sensitive to parsley, carrots, fennel, or celery. Skin rashes and hives have been reported. Pregnant women should avoid parsley oil. It is stronger than other forms of parsley and may cause miscarriage. Wash fresh parsley with water before use to remove bacteria.

Peony: Peony root may have antioxidant effects. More research is needed to better understand the antioxidant potential of peony.

Avoid if allergic or sensitive to peony. Avoid with bleeding disorders or if taking drugs, herbs, or supplements that increase bleeding risk. Use cautiously with estrogen-sensitive cancers or if taking drugs, herbs, or supplements with hormonal activity. Avoid if pregnant or breastfeeding.

Pomegranate: Early studies suggest that pomegranate juice may have antioxidant properties, but the effects in humans are still unclear. Additional studies, including those in specific disease states in which free radical oxidation is prominent (such as diabetes and cancer), are warranted.

Avoid if allergic or hypersensitive to pomegranate. Avoid with diarrhea or high or low blood pressure. Avoid taking pomegranate fruit husk with oil or fats to treat parasites. Pomegranate root/stem bark should only be used under supervision of a qualified healthcare professional. Use cautiously with liver damage or disease. Pomegranate supplementation can be unsafe during pregnancy when taken by mouth. The bark, root and fruit rind can cause menstruation or uterine contractions. Avoid if breastfeeding due to a lack of scientific data.

Pycnogenol®: Due to conflicting study results, it is unclear if Pycnogenol® has significant antioxidant effects in humans. Further research is necessary.

Avoid if allergic/hypersensitive to Pycnogenol®, its components, or members of the Pinaceae family. Use cautiously with diabetes, hypoglycemia, bleeding disorders. Use cautiously if taking hypolipidemics, medications that may increase the risk of bleeding, hypertensive medications, or immune stimulating or inhibiting drugs. Avoid if pregnant or breastfeeding, or in young children.

Raspberry: Several laboratory studies have shown that raspberry contains antioxidants and has antioxidant activity. Preliminary study indicates that a beverage containing several juices, including raspberry, has postexercise antioxidant effects. However, larger studies using raspberry alone are needed.

Avoid if allergic or hypersensitive to raspberry (Rubus idaeus ), its constituents, or any members of the Rosaceae family. Use cautiously with asthma or if taking Clotrimoxazole, antibiotics (especially clarithromycin), antispasmodic agents or muscle relaxants, diuretics, salicylates, or laxatives, sedatives or operating heavy machinery. Use cautiously if pregnant or breastfeeding as raspberry may theoretically induce labor. Cyclosporiasis associated with contaminated fresh raspberries has been reported. Always thoroughly wash raspberries before ingestion.

Resveratrol: Resveratrol has been included in herbal products that are marketed to increase lifespan and prevent aging. Limited evidence shows a possible benefit for this use. More studies are needed in this area.

Avoid if allergic or hypersensitive to resveratrol, grapes, red wine or polyphenols. Resveratrol is generally considered safe. It is commonly found in food and beverages. Use cautiously with bleeding disorders, abnormal blood pressure. Use cautiously with drugs that are broken down by the body's cytochrome P450 system. Avoid if pregnant or breastfeeding.

Sea buckthorn: Sea buckthorn extract taken with blueberry extract may have antioxidant properties. More study is needed in this area before a conclusion can be made.

Avoid if allergic or hypersensitive to sea buckthorn, its constituents, or members of the Elaeagnaceae family. Use cautiously in patients with cancer, hypertension or bleeding disorders. Avoid higher doses than food amounts if pregnant or breastfeeding.

Seaweed: Fucoidans from some brown algae, including bladderwrack (F. vesiculosus),exhibit some antioxidant activity in vitro. Human research is lacking.

Avoid if allergic or hypersensitive to Fucus vesiculosus and iodine. Avoid with history of thyroid disease, bleeding, acne, kidney disease, blood clots, nerve disorders, high blood pressure, stroke, or diabetes. Avoid if pregnant or breastfeeding.

Selenium: It has been proposed that selenium supplementation may help people live longer. However, results from clinical trials are mixed, and it is still unclear whether selenium supplementation can increase lifespan in healthy individuals. More research is needed to better determine the effects of selenium on aging.

Use cautiously at doses from 27-2,310 milligrams daily, as well as in patients on hemodialysis, in patients with iodine deficiency, high cholesterol, or immune disorders, and in those using immunosuppressants, corticosteroids, antacids, erythropoietin (EPO), cholesterol-lowering medications, oral contraceptives, astragalus, or iron supplements. Avoid in patients at high risk of nonmelanoma skin cancers or at risk for developing diabetes. Avoid in patients with known allergy or hypersensitivity to products containing selenium; however, selenium is a trace element, and hypersensitivity is unlikely.

Soy: There is some evidence in support of soy increasing antioxidant status in humans. In general, diets high in plant foods may offer antioxidant benefits. Further research is required in this field before a conclusion can be made.

Avoid if allergic to soy. Breathing problems and rash may occur in sensitive people. Soy, as a part of the regular diet, is traditionally considered to be safe during pregnancy and breastfeeding, but there is limited scientific data. The effects of high doses of soy or soy isoflavones in humans are not clear, and therefore are not recommended. There has been a case report of vitamin D deficiency rickets in an infant nursed with soybean milk (not specifically designed for infants). People who experience intestinal irritation (colitis) from cow's milk may experience intestinal damage or diarrhea from soy. It is not known if soy or soy isoflavones share the same side effects as estrogens, such as an increased risk of blood clots. The use of soy is often discouraged in patients with hormone-sensitive cancers, such as breast, ovarian or uterine cancer. Other hormone-sensitive conditions such as endometriosis may also be worsened. Patients taking blood-thinning drugs like warfarin should check with a doctor and pharmacist before taking soy.

Tocotrienols: Tocotrienols have been studied for their antioxidant properties in preliminary studies. However, few clinical trials exist. Based on a case series, PalmVitee®, a tocotrienol enriched fraction of palm oil, demonstrated antioxidant properties in patients with cerebrovascular disease. Additional high-quality clinical studies are needed before a firm conclusion can be made.

Use doses higher than 400 IU daily cautiously. Use cautiously in individuals with diabetes or those using hypoglycemic agents. Use cautiously in individuals with bleeding disorders or those using anticoagulant or antiplatelet agents. Use medicinal amounts cautiously in pregnant and lactating individuals. Avoid with known allergy/hypersensitivity to sources of vitamin E, tocopherols, and tocotrienols. Tocotrienols are a type of vitamin E. Skin reactions such as contact dermatitis and eczema have been reported with topical vitamin E preparations, such as ointments or vitamin E containing-deodorants. Individuals with known or suspected hypersensitivity to vitamin E should avoid these products.

Vitamin A: In humans, the benefits of vitamin A for potential antioxidant activity are not clear. Additional research is needed in this area.

Avoid if allergic or hypersensitive to vitamin A. Vitamin A toxicity can occur if taken at high dosages. Use cautiously with liver disease or alcoholism. Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or heart disease. Vitamin A appears safe in pregnant women if taken at recommended doses; however, vitamin A excess, as well as deficiency, has been associated with birth defects. Excessive doses of vitamin A have been associated with central nervous system malformations. Use cautiously if breastfeeding because the benefits or dangers to nursing infants are not clearly established.

Vitamin E: Vitamin E possesses antioxidant activity, but it is not clear if there is any benefit in humans. The American Heart Association has recommended obtaining antioxidants such as vitamin E by eating a well-balanced diet high in fruits, vegetables, and whole grains, rather than from supplements, until further scientific evidence is available.

Avoid if allergic or hypersensitive to vitamin E. Avoid with retinitis pigmentosa (loss of peripheral vision). Use cautiously with bleeding disorders or if taking blood thinners. Avoid above the recommended daily level in pregnant women and breastfeeding women.

Yoga is generally considered to be safe in healthy individuals when practiced appropriately. Avoid some inverted poses with disc disease of the spine, fragile or atherosclerotic neck arteries, risk for blood clots, extremely high or low blood pressure, glaucoma, detachment of the retina, ear problems, severe osteoporosis, or cervical spondylitis. Yoga should not be used as a substitute for standard care, especially for potentially dangerous ailments such as asthma. Patients should seek the guidance of a qualified healthcare provider before starting any regimen of treatment. Certain yoga breathing techniques should be avoided in people with heart or lung disease. Use cautiously with a history of psychotic disorders. Yoga techniques are believed to be safe during pregnancy and breastfeeding when practiced under the guidance of expert instruction (the popular Lamaze techniques are based on yogic breathing). However, poses that put pressure on the uterus, such as abdominal twists, should be avoided in pregnancy.

Oxidation is a chemical process in which electrons from a substance are transferred to what is known as an oxidizing agent. Oxidation reactions may produce substances referred to as "free radicals." These molecules may cause chain reactions that can damage many cells in the body. Antioxidants may stop the chain reactions caused by free radicals, and therefore stop the process of this sort of damage occurring in the body. In other cases, antioxidants may stop other kinds of oxidation reactions by becoming oxidized themselves and thus sparing cells and tissues from damage. The potential medical benefit of antioxidants may reside in their ability to prevent or slow the oxidation of molecules in the microscopic parts of the body, such as DNA or proteins.

The most common theory of aging is called the free radical theory. Many researchers believe that free radicals may cause extensive damage to the body's tissues. Although free radicals are needed for the body to produce energy, maintain immunity, transmit nerve signals, produce hormones, and contract muscles, they may also contribute to the process of aging. Free radical damage begins at birth and continues through adulthood. However, when individuals are young, the effects are minimal because the body has many different ways to repair and replace cells to maintain proper functioning. As individuals age, the damage caused by free radicals increases.

Antioxidants are found in varying amounts in foods such as vegetables, fruits, grain cereals, legumes, and nuts. Some antioxidants such as lycopene and ascorbic acid can be destroyed by long-term storage or prolonged cooking. Other antioxidant compounds are more stable, such as the polyphenolic antioxidants in foods such as whole-wheat cereals and tea. In general, processed foods are thought to contain less antioxidants than fresh and uncooked foods since preparation processes may expose the food to oxygen. In addition to being available in a variety of fruits and vegetables, antioxidants are available as supplements. They are one of the most popular categories of supplements available today. Some of the most popularly used antioxidants are ascorbic acid (vitamin C), glutathione, lipoic acid, carotenes, ?-tocopherol (vitamin E), and ubiquinone (Coenzyme Q10).

Experts have suggested that in order for antioxidants to be possibly beneficial, a person must consume them on a regular basis over a period of many years as the proposed benefits of antioxidants may occur by possibly stopping many oxidation reactions over long periods of time. Therefore, consuming a large number of antioxidant supplements over a day, week or month may not reverse the damage that has already been done by free radicals.

Diet:

Food groups: An appropriate amount of fruits and vegetables should be consumed to stay within one's energy needs. Two cups of fruit and 2 1/2 cups of vegetables per day are recommended to achieve a 2,000-calorie intake. Food portions may need to be adjusted depending on the calorie level.
Vegetables should be selected from all five groups (dark green leafy vegetables, orange vegetables, legumes, starchy vegetables, and other vegetables) several times a week.

At least three-ounce-equivalents of whole-grain products should be consumed each day. Additionally, the remaining grains should come from enriched or whole-grain products. At least half the grains should come from whole grains.
Three cups of fat-free or low-fat milk or equivalent milk products should be consumed daily.

Atkins dietT: Despite the common public perception that the Atkins dietT permits an unlimited consumption of greasy foods, it is actually recommended that dieters consume primarily lean meats, such as seafood and poultry. Like many diet plans, the Atkins dietT requires regular consumption of nutritional supplements, such as a multivitamin pill, and adherence to a regular exercise plan. The Atkins dietT does not recommend that individuals adopt the eating plan unless they abide by the nutritional supplements and exercise routine. A qualified healthcare professional should be consulted before beginning any new diet.

Under the Atkins dietT, it is recommended that dieters stop any unnecessary medications. Any changes to medications should be discussed with a qualified healthcare professional.
When combined with this diet, diuretics, and, to a lesser extent, other cardiovascular medications and diabetes medications, including insulin, may produce a dangerous overdose. Psychotropic drugs, phenothiazines and antidepressants such as Prozac®, tranquilizers, lithium, and similar drugs, may cause metabolic resistance to the diet. Estrogen, prednisone, and other steroids, and antiarthritic drugs, especially NSAIDS, may cause weight gain or prevent weight loss. For persons metabolically resistant, any medications may aggravate the condition.

During the induction period (the first two weeks), dieters are permitted to eat no more than 20 grams of carbohydrates per day with a diet consisting of nearly unlimited meats, poultry, seafood, eggs, cheeses, oils, butter, margarine, bacon, and sausages. The 20-gram carbohydrate limit is generally derived from trace amounts of carbohydrates in sauces, dressings, cheeses, and a couple cups of lettuce greens or vegetables daily. During these two weeks, participants are not allowed to have any milk, fruits, grains, cereals, breads, or "high glycemic index" vegetables such as potatoes, peas, corn, and carrots.

During the maintenance period, dieters consume no more than 90 grams of carbohydrates daily.

DASH diet: The DASH diet is based on the U.S. Department of Agriculture (USDA) food pyramid. It has been evaluated in medical trials conducted in the late 1990s and early 2000s and has been shown to reduce blood pressure. The National Heart, Lung, and Blood institute updated the diet specifications after the USDA released an updated food pyramid in 2005.

Unlike other diets designed for individuals with high blood pressure, the DASH diet does not make the levels of sodium in the diet the primary focus. However, salt reduction is an important component of the diet. According to the DASH diet, an individual should consume a maximum of 2,400 milligrams of sodium daily. Individuals are encouraged to pay attention to all of the salt in one's diet, including table salt and salt used in cooking, as well as so-called "hidden salts" in fast foods, processed foods, and foods eaten at restaurants.

Avoiding or reducing consumption of foods such as canned soups, lunchmeats, and junk foods may significantly decrease a person's sodium intake. As a reference, one teaspoon of salt contains 2,000 milligrams of salt.

Ornish diet: The Ornish diet is a low-fat vegetarian way of eating, with less than 10% of daily calories from fat (an average of 15 to 25 grams of fat per day), 70-75% from carbohydrates, and 15-20% from protein. This diet encourages consumption of beans, fruits, vegetables, and whole grains, and it limits intake of processed foods, high-fat dairy products, simple sugars, and alcohol.

Dr. Dean Ornish, a physician who has directed clinical research for the past 25 years, created this diet as a lifestyle modification to reverse existing heart disease by emphasizing foods that are very low in fat yet filling, such as high-fiber grains and legumes (i.e., beans and peas). In addition to the proposed heart-healthy effects of the Ornish diet, patients may also lose weight. Based on Ornish's research, patients lost an average of 25 pounds over the course of a year.

The Ornish diet is completely vegetarian. Cholesterol and saturated fat are excluded; no animal products (except egg whites and nonfat dairy products) are allowed. All nuts, seeds, avocados, chocolate, olives, coconuts, and oils are eliminated, except for a small amount of canola oil for cooking and oil that supplies omega-3 essential fatty acids. The Ornish diet also prohibits caffeine but allows a moderate intake of alcohol and salt. There is no restriction on calorie intake. Several small meals a day rather than three large meals is also recommended.

South Beach DietT: The South Beach DietT is a low-carbohydrate diet. Low carbohydrate diets aim to avoid carbohydrates that may spike insulin levels in the body. When a carbohydrate is high in what is considered by some as "bad" carbohydrates, a large burst of insulin is released from the pancreas in response to a drastic elevation in glucose in the blood.

The high insulin levels do not allow glucose to be converted into glucagon, the form of sugar that allows for fat to be used as energy. Instead, these high insulin levels promote the storage of fat in the body. Proponents believe that by avoiding these carbohydrates, individuals could avoid the storage of additional fat, as well as allow for current fat stores to be used as energy.

The South Beach DietT consists of three phases: 1. "kick-starting" weight loss, 2. reintroducing the "right" carbohydrates, and 3. "a diet for life." Phase 1 is intended to be followed for 2 weeks. Phase 2 is intended to last for as long as necessary to lose the desired amount of weight. Phase 3 is focused on maintaining a healthy weight.

Exercise:

Aerobic activity: The American Heart Association states that all healthy adults aged 18-65 years need moderate-intensity aerobic physical activity for a minimum of 30 minutes five days each week. Vigorous-intensity aerobic activity may be substituted instead, for a minimum of 20 minutes three days each week. Additionally, exercise combinations such as walking briskly for 30 minutes twice during the week and then jogging for 20 minutes on two other days is sufficient.

Muscle-strengthening activity: It is recommended that 8-10 exercises be performed on two or more nonconsecutive days each week using the major muscle groups. Muscle-strengthening activities include a progressive weight-training program, stair climbing, and similar resistance exercises that use the major muscle groups.

It is currently unclear if oxidants cause disease, or if oxidants are produced as a result of the disease. Regardless, the stress caused by oxidants over long periods of time is thought to play a role in the development of many types of diseases, including heart disease, rheumatoid arthritis, Alzheimer's disease, Parkinson's disease, some conditions associated with diabetes, and some types of diseases where the brain loses its ability to function properly. The role of free radicals in heart disease is better understood than in other types of diseases. The arteries may harden due to oxidation of cholesterol, and over time, this process may result in heart disease.

The first large randomized trial on antioxidants and cancer risk was the Chinese Cancer Prevention Study, which was published in 1993. This trial investigated the effect of a combination of beta-carotene, vitamin E, and selenium on cancer in healthy Chinese men and women at high risk for gastric cancer. The study showed that the combination significantly reduced incidence of both gastric cancer and cancer overall.

The 1999 Women's Health Study (WHS) tested effects of vitamin E and beta-carotene in the prevention of cancer and cardiovascular disease among women age 45 years or older. Among apparently healthy women, there was no benefit or harm observed from beta-carotene supplementation. The Selenium and Vitamin E Cancer Prevention Trial (SELECT) is currently investigating whether taking selenium and/or vitamin E supplements may prevent prostate cancer in men age 50 or older. The Physicians' Health Study II (PHS II) is a follow-up of the earlier clinical trial by the same name and is currently investigating the effects of vitamin E, vitamin C, and multivitamins on prostate cancer and total cancer incidence.

Diet:

Atkins dietT: The Atkins dietT is based on the theory that overweight people eat too many carbohydrates. Bodies burn both fat and carbohydrates for energy, but carbohydrates are used first. By drastically reducing carbohydrate intake and increasing protein and fat intake, the body will, in theory, naturally lose weight by burning stored body fat more efficiently. Some experts have attributed the success of the Atkins dietT to a significantly reduced intake of calories, rather than changes in the body's metabolism. However, the specific way that the Atkins dietT changes the body's metabolism is unknown.

DASH diet: The DASH diet was based in part from data about the lower incidence of certain health problems experienced by vegetarians. It has been found that vegetarians tend to have a lower risk of suffering a stroke, heart attack, or kidney failure due to high blood pressure because individuals who follow a vegetarian diet tend to have lower than average blood pressure. A vegetarian diet also tends to be higher in unsaturated fat, fiber, calcium, potassium, and magnesium than other diets. A 2006 trial by Elmer et al. evaluated several behavioral interventions to lower blood pressure and improve lifestyle behaviors of patients with high blood pressure. The length of the trial was six months. Patients who followed the DASH diet showed a statistically significant reduction in weight and sodium and fat intake. In addition, these individuals also statistically increased their intakes of minerals, fiber, dairy, fruits, and vegetables. The authors concluded that patients who undergo and sustain multiple lifestyle modifications, such as those required by the DASH diet, improve their blood pressure readings and may reduce their risk for chronic disease.

Ornish diet: The Lifestyle Heart Trial studied the effects of the Ornish diet. On average, Dr. Dean Ornish's patients lost 24 pounds in a year and had a 37% reduction in low-density lipoprotein (LDL) cholesterol levels; high-density lipoprotein (HDL) cholesterol levels were unchanged. Additionally, there was a 91% reduction in angina frequency (chest pain) and a significant degree of angiographically measured coronary stenosis regression. It was unclear to what degree other lifestyle modifications such as exercise and stress reduction, which are integral parts of the Ornish program, played in these results. Another study compared the Atkins, Ornish, Weight Watchers, and Zone diets. The study set out to assess adherence rates and the effectiveness of the four popular diets for weight loss and cardiac risk factor reduction. Each diet was shown to significantly reduce the LDL/HDL cholesterol ratio by approximately 10% with no significant effects on blood pressure or glucose after one year. For each diet, decreasing levels of total and HDL cholesterol, C-reactive protein, and insulin were significantly associated with weight loss, with no significant difference between diets.

Overall, there are mixed findings about the Ornish diet's efficacy (low carbohydrate, calorie restriction, etc.) compared with other diets. However, most results seem promising, and the Ornish diet and lifestyle modification may be effective in reducing cardiac disease risks and aiding in weight loss.

South Beach DietT: Recent studies have shown that patients placed on low-carbohydrate diets such as the South Beach DietT lost more weight than similar patients placed on low-fat diets, such as the National Cholesterol Education Program (NCEP) diet or the American Heart Association diet. Additionally, these patients also had greater decreases in triglyceride levels at the end of the studies. Other studies have duplicated these results and suggested that these low-carbohydrate diets not only increase weight loss but also decrease markers for cardiovascular disease, for example LDL cholesterol levels. Experts suggest that even though this diet may be healthier than other low-carbohydrate diets because it includes most of the major food groups, most of the weight lost in the first phase has been found to be water weight.

Exercise:

Exercise helps to promote overall health and may decrease the risk of developing illnesses, such as heart disease. There is extensive scientific evidence suggesting that regular exercise offers major health benefits. According to the U.S. Centers for Disease Control and Prevention (CDC), the failure to exercise regularly is a significant precursor to heart disease, stroke, diabetes, and cancer. According to the U.S. Department of Health and Human Services and the U.S. Department of Agriculture (USDA), poor diet and physical inactivity may be associated with a variety of conditions, including cardiovascular disease, type 2 diabetes, hypertension, osteoporosis, and certain cancers. Current opinion finds that regular exercise boosts energy, encourages healthy sleep patterns, and helps individuals maintain a regular weight. All major medical organizations recommend exercise as one of the most important ways to stay healthy and recover after illness.

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.